UAE: Al Bahar Towers Moving Closer to Truly Sustainable Construction

While the Al Bahar towers in Abu Dhabi have received acclaim and accolades as pillars of sustainable design, the project’s lead designer says that they are merely one step towards truly sustainable construction

The 25-storey skyscrapers, which serve as the Abu Dhabi Investment Council’s (Adic) headquarters, have an external facade composed of 2,000 umbrella-like elements. These follow the sun, closing to block out heat while allowing in light. An array of solar panels on the roof is also utilised to heat water.

However, the towers’ designer, Abdulmajid Karanouh, director of facade design and engineering at the Ramboll engineering group, says an inventive, sustainable shell cannot make up for an old-fashioned, unsustainable core.

“First of all, those two towers are not sustainable towers. They were not designed to be sustainable towers,” he says.

“When I say this, people go mad, they go crazy, they start banging their hands against the table saying: ‘What are you on about? They have won loads of awards based on their sustainable features’.”

His clients wanted a sustainable office building of the western type with concrete blocks, a steel structure and a panoramic glass facade — the “ubiquitous or the mainstream office that you find here in the UAE”, as Mr Karanouh says.

Skyscrapers with glass facades have huge surface areas and absorb great deals of heat — especially in the UAE. “When you’re building in literally one of the sunniest areas of the world, then you start questioning the wisdom behind using fully glassed buildings or facades,” Mr Karanouh says.

This is one of the most significant misunderstandings in construction, he says; there still does not exist a “sustainable” skyscraper — especially not one with a panoramic glass facade. The amount of energy needed to cool, ventilate and light such buildings renders them extremely heavy users of resources.

To make an unsustainable type of skyscraper more energy-efficient, Adic eventually approved a design that wrapped each tower in a veil.

Mr Karanouh says that although people often focus on a façade’s U-value (the insulation characteristics of a material), it is really the G-value (the shading coefficient) that is important.

“When you’re in such an intensely sunny region, in any building, 70 per cent of air conditioning is resulted from direct exposure to solar rays,” he says.

The Al Bahar facade mitigates such heat transfer by 50 per cent, reducing carbon dioxide emissions by 1,750 tonnes a year. The system allows natural light through, reducing the need for artificial lighting. In the end, the true success of the buildings, Mr Karanouh says, is that unlike so many high-rises, they suit the region.

“Even if the mashrabiya [the facade] is closed, you can still see through it. Inside the building, you can barely hear or feel the air conditioning. That means less consumption of fossil fuels. So genuinely addressing a problem lends itself to a more sustainable solution.”

As builders worldwide gravitate towards greater sustainability, their arguments for so doing come not only from ecology but from economics: that the resources you end up saving are, in the end, your own.

“A common issue being discussed around here is cost versus sustainability,” says Saeed Alabbar, the chairman of the Emirates Green Building Council. “There is data around the world, [such as the] research that the World Building Council did with McGraw-Hill Construction, which indicated that there are premiums that sustainable buildings can attract. That’s a large reason why developers are voluntarily going beyond the codes to build more sustainably around the world.”

A thin majority of the McGraw-Hill study’s respondents predicted that 60 per cent of their work would be sustainable by 2015 — a trend driven largely by market demand. Seventy-six per cent said that sustainable construction lowered operating costs and 38 per cent said it raised building values.